<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>太极图</title>
		<style>
			div{
				width: 100px;
				height: 50px;
				background: whitesmoke;
				border-bottom: solid 50px black;
				border-radius: 50%;
			}
		</style>
	</head>
	<body>
		<div></div>
	</body>
</html>
